mam_update_admit created .mam/ to hold its lock, so a checkout running its own run_loop.sh got a .mam (test_loop_marker_isolation L1, test_issue17 W1). A tree without .mam is not an installed workspace, the only kind the update runs in, so the gate admits there without a lock. The update's monitor-stop wait is a normalised integer knob and is listed in INT_KNOBS (test_issue26_ints B5). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>